Up to 60% of individuals with schizophrenia do not take their antipsychotic medications as prescribed, which can lead to symptom relapse, decreased functioning, hospitalization, and increased healthcare costs. Recent studies of both patient- and pharmacy-based interventions utilizing behavioral tailoring, environmental supports, and medication monitoring have shown promise in improving antipsychotic adherence. However, there is continued need for effective adherence-enhancing interventions (AEIs) that are less resource intensive and more widely accessible by the broad range of individuals in need of assistance with medication management. Over the last decade, technological advances in internet and cellular communication, including the emergence of mobile 'smartphones', have revolutionized the way our society communicates. Whereas a variety of mobile phone-based applications have been shown to be effective for improving health outcomes such as medication adherence for a number of medical conditions, few such applications have been developed for individuals with schizophrenia. Therefore, in response to NIMH PAR-09-173, we propose to develop and pilot test the effect of a mobile smartphone intervention, MedActive, on improving antipsychotic adherence among this population. We used the Information-Motivation-Behavioral (IMB) Skills Model of adherence as the theoretical framework to inform the conceptualization of MedActive. The IMB Skills Model posits that individuals who are well-informed and motivated to adhere will enact adherence-related behavioral skills that lead to adherence behaviors and favorable health outcomes. MedActive will provide personalized reminders to patients to take their antipsychotic medications as prescribed and will query them about their intentions to take the medication, the occurrence of side effects, and the presence of positive psychotic symptoms. Summaries of these ecological momentary assessments of adherence, symptoms, and side effects will be made available to the individual on the phone and to their psychiatrist through a secure, online clinician interface. Using an iterative user-centered design approach, the specific aims of this proposal are to (1) collaborate with individuals with schizophrenia, psychiatrists and an expert advisory group to develop the initial version of MedActive; (2) conduct laboratory usability testing and a short-term field trial in 10 individuals with schizophrenia and their psychiatrists to determine the preliminary acceptability and feasibility of MedActive in clinical practice; and (3) conduct a randomized pilot trial of MedActive compared to providing a smartphone alone in 40 individuals with schizophrenia and their psychiatrists to evaluate its effect on antipsychotic adherence. We will also explore whether psychiatric symptoms and neuropsychological impairments moderate the effect of MedActive on adherence. If shown to be effective, MedActive will introduce a paradigm shift in medication self-management by individuals with schizophrenia and in treatment monitoring by their clinicians.